Hi,
The liquid nystatin is vile-tasting,

but I must say it does work if you keep using it (and do whatever else you can to keep yeast to a minimum). I don't know about the tablets, but I would think that the liquid would be better because it coats the whole mouth if you swish it around.
My doctor recommended a book called 'The Body Ecology Cookbook' and actually uses it himself. Though if someone is in recovery from Lyme I doubt if they're going to be able to do much if any cooking at all. Thought I 'd mention it though.
I've never tried them myself, but there are a number of herbal yeast control systems, such as Candida Cleanse. Worth a try, maybe.