I bought some beakers for exactly that purpose. They are heat resistant similar to Pyrex but thinner and taller. It still takes a fair amount of plastic as each dip layers 4 rods. 2nd dip is 8x the plastic, etc.. Microwave worked well and when I was dipping two color baits I also used a griddle to maintain heat after I microwaved. Needs to be stirred to keep temps but works ok.
The injection molds work great and use less plastic. Much less "waste". I've purchased molds form a few different manufacturers and they all shoot well so just investigate body diameter / thickness needs.