I answered a similar question on leather products here:
How to wash leather shin guard?
You can apply the same formula to vinyl/PU synthetic material. If anything, leather is much more fragile to wash than vinyl/PU, so with leather you have to make sure you dry it immediately. Submerging leather in soapy water is generally only done if the foam inside is soiled (and you can't remove the leather shell in order to wash separately). And with leather, you really have to be careful to dry it well afterward.
For vinyl/PU, you can submerge with impunity! Just squish it out dry and then hang up to air dry afterward. Unlike leather, vinyl/PU material is fine with water. If you let it air dry, it won't get moldy. And vinyl/PU won't crack and degrade with exposure to water like leather products can.
If it's been in contact with animal feces or urine, after submerging in soapy water and rinsing it out with clean water, submerge it again in a diluted bleach solution. Leave it in there for 5 minutes. Then rinse again several times in clean water. Squish it out inside of dry towel. Then hang up to air dry.
As always with diluted bleach, test on a small area first. And follow the instructions for dilution on the bottle.
If your gear permits removing the outer shell, remove it and wash the shell and foam insulation separately. Usually the foam is glued to the inside, however.
One final thought: There are alternatives to bleach, but bleach is best. Diluted hydrogen peroxide is another thing you can try. And while vinegar is often recommended as a way to cut down on odors, it's not a very good disinfectant.
Hope that helps.