I’ve actually heard that. Coca-Cola will clean off car battery acid, so I imagine resin incense wouldn’t be able to put up much resistance to it.
If your thurible is silver, you may wish to try denture cleaning tablets. This was a suggestion given to me by a monk at the abbey where I went on retreat last summer. If your thurible is brass, however, proceed with caution. I don’t know why—that’s just what I was told. Both of ours are brass so I have never tried the denture cleaning tablet approach.
If your thurible hasn’t been cleaned in years and/or is damaged, your best bet is to have it professionally restored. This is potentially expensive, however, particularly if precious metals are involved.
I did speak to the manufacturer of our main thurible, and they said for the particular model we have I could even use steel wool on it :eek: YMMV. I’m only telling you this to illustrate the range of possible approaches. Please do not try this without talking to the manufacturer of your own thurible first. I cannot stress this enough!!
Chain entanglement: Our secondary thurible is a five-chain model (the main thurible has a single heavy chain) with both a ring around all the chains and a round metal plate to which the chain ends not attached to the thurible itself are fastened. In my experience it is the plate that prevents the chains from getting tangled, not the ring. As AngelusDomini said, the ring makes the thurible easier to handle.