EVAPO-RUST AND A FUEL SENDING UNIT

I only use rust converters or removers on floor pans and light rust.
I've moved on to electrolysis rust removal for parts.
a little super washing soda in a container big enugh to submerge the part, rebar,wire and an old battery charger or power supply saves a lot of mess and headache.
You can't beat it for gas tanks. and you don't have to clean all of the rocks out.