This is why valves are not useful and not accepted.
If your mask gets moisture-saturated, just replace it.
Why? All of these measures are probabilistic.
P(infect others) = P(infected) * P(transmission)
Simple masks don't have much impact on P(infected), but substantially reduce P(transmission) under some circumstances. Valved FFP3 don't have much impact on P(transmission) [not zero], but vastly reduce P(infected) in virtually all circumstances. It's not clear to me even under this simplistic analysis that it is not superior. And in an enclosed space, the effect of simple masks on P(transmission) is almost wiped out.
>If your mask gets moisture-saturated, just replace it.
New mask every 2 hours?
In a public space there is simply no way of efficiently knowing and verifying everybodies P(infected), thus the only remaining measure is to reduce P(transmission).
And yes, if that‘s the time it takes for your mask to get wet, then it is time to replace it.