I hear at Walmart garage you can get a tranny flush where all or most fluid is flushed. Is this recommended over just draining plug and dropping the pan?

If after draining by removing plug and then dropping pan, will there still be lots of fluid gushing?

 

the tranny hold 10 guarts, the pan itself only holds about 4

 

Drop the pan, I had a ton of tiny metal shavings stuck to the magnet