The bags get wiped every night and they still smell by week six. That pattern points at the construction rather than at the crew.

Where the spill actually goes

A stitched liner is perforated by definition: every stitch is a hole.

Liquid passes through the holes into the foam panel, which is porous and unreachable.

Why cleaning cannot fix it

You can only wipe the surface you can reach, and the residue is behind it.

Washing the bag makes it worse: water enters the foam far more easily than it leaves.

What a welded liner changes

Heat-sealed or RF-welded seams give a continuous tray with nowhere for a spill to go.

One wipe removes what a stitched bag would have absorbed permanently.

If you already own stitched bags

Use a removable wipeable insert as a barrier and replace the worst bags first.

Then specify welded liners on the next order, because the smell is a build problem.