I think that the only time I ever used the charm from the cloak was in an experiment during an extended manhunt by the forces of law and order in Baldur's itself. I charmed one Fist in my pursuit of carrying out several missions around the city. Yeah, yeah, I know, I should have done all that before I went back to Candlekeep, but there you go. (It was more interesting that way strangely, also you get to see Imoen and Minsc rushing around killing civilians because they turn hostile if you kill a guard
.)
BTW Six', when you turn into a wolf using that cloak, can you turn back? I never seemed to be able to - and you've got to experiment - but the item description seems to suggest that it didn't work for its creator and not anybody else. Mind you, its a while since I sold it (naturally) so my recollection may be a little hazy...
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Making running away an art form