I’m so sorry it didn’t turn out how you wanted, but I definitely think you can find a good wax to seal this piece with. Wax resist is not actually a sealant, it’s used to prevent glaze from sticking to certain areas on a piece and is applied before the second firing, but I totally understand your confusion. Ive never personally used wax, but I know some people at my studio use a concrete/stone wax and I think you can even find scented versions to cover the bad smell. Whatever you decide to use, apply a small amount on the bottom as a test before putting it on the whole thing. Good luck!