My best suggestion would be to hang them outside in the sun.

I either use eco powder, or nothing with my nappies & haven't had a problem with smell. Maybe its what the nappies are made from? I know hemp smells different to bamboo when a nappy is full. Microfibre smells different again. I prefer bamboo for that reason. But they all smell with a full nappy! Rolling over to DD in the mornings isn't pretty sometimes

I strip wash in hot water with a couple drops of eco dish washing liquid.
You can also soak all your boosters for a few hours. Boosters only though.
And sun. Lots of it... (dunno how that'll go for you over there )

With the leaks, if none of that works, is it possible bub has changed shape a bit? I've had about a month being lazy & using sposies & now I'm back to cloth some aren't fitting as well as they were & we're getting leaks.