Help cleaning a memory foam mattress topper DS wet our bed!

DP and I have a memory foam mattress topper on our bed.
DS jumped into bed with us last night (usual occurance, he sleeps on a mattress next to our bed, but jumps in for cuddles at about 5am)
Last night I didnt put a pull up on him, he didnt wet his bed, but woke himself up this morning (after I had already gotten up) as he was wet.
So is our bed.

I have googled a bit about care of the memory foam, DP seems to think it will be ok in the washing machine, but it is queen sized so I'm not sure our front loader will cope with the bulk of it.
Also everything I have read says not to fully immerse in water.

Has anyone else had any experience with this?

We have a similar mattress to yours except that our topper doesn't come off. I dried as much of the wet area with a dry absorbent cloth/towel then with a damp cloth went over the area then dried it again as much as possible. From the supermarket I bought a product called Protect-A-Bed - Odour Eliminator Fabric Treatment. It is in a pink box with pictures of people on the front. It is suppose to get rid of the smell of urine, vomit etc... You spray it on the area, rub in then let it dry. We have an overhead fan so that helped with the drying process. I can't smell anything on ours or DD mattress (she has had a wee accident and also vomitted)
GL

Thank you!