I would calmly ask him if he took the cleaning supplies and if so, where. If he did take them to the OW I would calmly set a boundary and explain to him why that is unacceptable. He may feel that he is "paying for everything" (his words which you quoted) and is entitled to take the supplies.
Beat me to the punch, Kara -- that's perfect.
AFG, I read your entire post, and you're like 10-for-10 in there, handling everything BEAUTIFULLY. I mean, "A+" stuff. Why would this boundary be any different, or any more difficult?
Psssshhh . . . . you've handled far tougher so far, baby!