A member of a Spanish group that I work with asked about Cistus Incanus. She knows that I am always interested in herbs — for two reasons, no prescription needed to get, likely less collateral damage than prescription medication. There are only 29 citations on PubMed. She reports very good response to it.The graphic below may explain part of the why.
UPDATED Mar,2020 — due to COVID-19. There are now 45 citations

from http://passion4luxus.com/?p=1904

“Cistus species … have been employed in Mediterranean folk medicine as herbal tea infusions for healing digestive problems and colds, as extracts for the treatment of diseases, and as fragrances…. Various preparations from Cistus species have traditionally been used as remedies in folk medicine around the Mediterranean basin, especially in Greece, Italy, Spain, and Turkey. The targeted conditions and diseases include anxiety, arthrosis, asthma, bronchosis, various types of cancer, bacterial and fungal infections, cardiopathies, catarrh, corn, diarrhea, duodenosis, dysendery, dyspnea, fracture, gastrosis, headache, hepatosis, hernia, hysteria, induration, infection, inflammation, insomnia, leukorrhea, myalgia, neuralgia, osteoarthritis, polyp, proctosis, rhinosis, sore, spasm, splenosis, ulcer, uterosis (Duke et al., 2008).

Organic and aqueous leaf extracts of C. monspeliensis, and also C. villosus (=incanus), growing naturally in Morocco and Tunisia were shown to have antimicrobial and antifungal properties that were mostly active against Staphylococcus aureus, Enterococcus hirae, and Pseudomonas aeruginosa and the yeast Candita glabrata (Bouamama et al., 2006).

Exhibited a rather weak activity against E. coli and P. aeruginosa, moderate against Candita albicans, Micrococcus luteus, and S. epidermidis, and most active against S. aureus and Bacillus subtillis (Demetzos et al., 1995), ” [2014]

• The effect of Cistus incanus herbal tea supplementation on oxidative stress markers and lipid profile in healthy adults. [2019] “Cistus incanus administration decreases cardiovascular risk factors including oxidative stress and dyslipidemia “
• CYSTUS052, a polyphenol-rich plant extract, exerts anti-influenza virus activity in mice. [2007]
• A polyphenol rich plant extract, CYSTUS052, exerts anti influenza virus activity in cell culture without toxic side effects or the tendency to induce viral resistance. [2007]
• Potent in vitro antiviral activity of Cistus incanus extract against HIV and Filoviruses targets viral envelope proteins[2016].
• Two new proanthocyanidin trimers isolated from Cistus incanus L. demonstrate potent anti-inflammatory activity and selectivity to cyclooxygenase isoenzymes inhibition[2015].
• The Polyphenolic Composition of Cistus incanus Herbal Tea and Its Antibacterial and Anti-adherent Activity against Streptococcus mutans [2015].
• Cistus incanus (CYSTUS052) for treating patients with infection of the upper respiratory tract. A prospective, randomised, placebo-controlled clinical study[2009]. “. In cell culture and in a mouse model it exerts antiviral and antimicrobial activities… A score of subjective symptoms decreased significantly over the course of treatment with Cistus, whereas treatment with placebo resulted in a less distinct decrease of symptoms. Among the inflammatory markers investigated, the C-reactive protein was mostly affected by Cistus and decreased significantly in the treatment group.”
• Antioxidant activity and protective effect on DNA cleavage of extracts from Cistus incanus L. andCistus monspeliensis L [2000].
• Antibacterial and antifungal activities of Cistus incanus and C. monspeliensis leaf extracts[1999]. “All extracts showed inhibitory activity against microorganisms.” [which ones were not named
• Gastroprotective effect of aqueous extract of Cistus incanus L. in rats [1995].
• Members of the same family appear to be antifungal [2007]

Bottom Line

Recommended:  E.Coli is almost resistant to it (for CFS a very good thing), it is very effective against S.Aureus (a strong suspect). It has also a long history of being used in folk medicine for digestive issues — the type of herbal usage signature that I look for!