Washing P&T main seat

[Grumpla]

I stuck the hood and basket in the machine and they've come up lovely, but I'm having trouble with the main seat. Tried scrubbing in the bath but obviously didn't get it rinsed well enough as there are now watermarks and it's still waterlogged after a day in the heat.

Can I pop it in the machine too? Or will this snap the back board thingy? Is there a way of removing this? I have an elderly E3 (v1).

Bump?

Aaargh! I washed it in the bath in the end and now I can't get the bloody thing dry. Has been out on the line two (baking hit) days in a row. In desperation I crammed it in the rumble dryer. The foam padding is still soaking wet so when you apply any pressure the moisture comes through.

Am I going to have to dismantle the whole bloody thing? I can see two seams to unpick (the bottom one and the one that 'hinges' between the two seat panels) should I do this to try and et the foam out? I'm worried the whole damn thing is going to go mouldy now

I know this an old thread, but i have this problem too.
Did you solve it in the end?
My toddler peed on main seat so i painstakenly took all fabrics of, washed everything in the washer except for mainseat that wouldn't fit.
I washed it in bath with washing powder and im yet to get it dry-any tips??