The problem with this is you are not dealing with a normal cleaning problem this is the same as dealing with a pet urine on a carpet. Under normal circumstances you would never clean a carpet by pouring buckets of water onto it but to deal with some urine you do need to do this and totally saturate the problem.
My suggestion of the washing machine is a last resort but I've done Jobs like this and normal pre- spraying & cleaning does not solve it ( it looks like you've cleaned it but it stinks)
We put our cushions in the wash monthly as we have 2 dogs who run around the garden then jump all over the suite, it does tighten them up and make them bend when put back on and they flatten out over time. The only problem we have had is the stitching snagging but the pillar case seams to solve this and offer some protection.
Like everything on here this is personel choice and not definitively correct.