Nah, it's never been fully watertight. I'm confident the bottom hatch is watertight, but it's the bit in the tub where the wires feed through that clearly can't be waterproof - that lets in some degree of water.
I mean, even when submerged for a short period the rx box doesn't fill up, so it's not too bad, but water does indeed get in. The connectors on my wires in the RX were corroding, so i cleaned them up and put CX on them and now they're tip top!
I didn't realise the SR400 was already waterproof, in fact I'm sure it's not, so I used CX on that also, there are pics of it on previous pages im sure.
As for the BEC, I tipped a load of CX into it before I installed it, and that seems to have taken care of business coz it's not blown, yet
You can also use some silicone on the ends instead of CX if it's easier for you?
Yeah show us some vids mate. Cleaning a waterproof rig isn't an issue - mine just gets sprayed with the hosepipe, then some WD-40 on the moveables to remove the remaining water - Job's a good en