The 2 stroke small HP Mercury outboards pick cooling water up through an opening underneath the anti-ventilation plate (sometimes incorrectly called the cavitation plate) just forward of the anode. There is a hose adapter, which has a single "muffler" and spring plate arrangement to hold the muffler over the cooling water inlet. The prop has to be removed to give clearance for the adapter.
That sounds like what I have.
I'll see if I can find a link to one on-line. If anyone happens to run across it please post it.
It will be a pain to remove the prop while it is in the water.
Maybe the bucket or bag idea will be easier.