"inflatable boots...Government issue". Ah, I think you've made the wrong assumption there. The US military issues "plastic" boots with an "inflation" valve to PARACHUTISTS. But the valve is not for inflation, it is there to allow pressure equalization when the occupant is being flown up to high altitudes--or jumping from the plan and experiencing sudden depressurization, which would make for a rather dramatic change of boot fit.
These are also called "Mickey Mouse" boots, after the big black "boots" seen on Mickey, as opposed to standard leather GI footwear. Been on the surplus market for a long time in black, and Winter White. Dunno how non-skid the Gi Rubber is but that's an interesting idea, they're usually well priced.