I dunno how you'd know but "clean" brothers do exist. Two of my cousins were raised quite religious but enough not to be totally suffocated and want the deen themselves. I've known them since I was like 5 and was joined to their hips from then to at least our late teens and can attest that these ninjas never swear, never watched or any of that, never dated and are just generally straight arrow religious young men. One is now engaged to a nice young Somali woman of the deen he met and courted in the proper way while doing his masters in Montreal and the other is still on the market but busy with work nowadays.