Stainless might not be perfect but it is the only metal I would trust in contact with the water and stainless steel is generally the only safe metal for water contact.
I've got some pipe clamps and stainless screws in the water myself.
Soaker hose may tend to clog up but then again, it is probably a scrap cut off anyway so it seems like a good deal to me.
Cuz zip tie wasn't tight enough and it leaked a lot of air.
You might try vinegar for your soak too perhaps if the clogging is due to hard water instead of just slime.
I do notice though that the 1/4" soaker I have requires more pressure to push air through it than a regular air stone.