Someone once told me the Rogochover says that Muslims are idol worshippers, as they secretly worship the moon.
I couldn't find where the Rogochover actually writes this. This article (fn. 20) says this claim is brought in HaRogochovi by Yair Bochorov, on p. 176, that it's מפי השמועה (an oral tradition). Apparently the sources for this tradition are found on p. 419, but I don't have access to it. This book also says that the Rambam only wrote otherwise because he lived under Muslim rule.
I would like the sources which report this claim, and sources which discuss reputability (ie: if he actually said it) or dispute it (ie: quoting the Rogochover and explaining why he's wrong).
Note: In case it's not obvious, I'm in no way advocating such a position. Anyone with a little exposure to Islam knows they're purely monotheistic. I merely seek sources regarding the position of the Rogochover.