Thanks to Kali for this Frugal Baby Tip!
I think the vinegar in the rinse and possibly another clear water rinse afterwards would help. Also, have you tried using a sprinkle of baking soda in the bottom of the pail? It really does absorb odor well. The vinegar I usually use is Brand X white vinegar. Not sure about the quality of the different ones (probably smell worse the cheaper you go).
Thanks to Cathy for this Frugal Baby Tip!
Or you can simply place some charcoal in a (empty) margarine tub, poke a few holes, and place in the bottom of the pail. Charcoal works well at absorbing odours!