The reason I used the Purple Stuff and tube method on the long piece was simply, that it was too long to fully submerge in the kiddy pool. You have to have the entire piece submerged otherwise you get uneven stripping and a big parting line in the trim piece.
Once the Purple Stuff did its work I then washed it in cold water and then transfered the straight trim piece to a section of plastic gutter lined with the same 6-ply plastic sheeting. I filled it with some of the same lye and water solution from the kiddy pool. You can see that the 2 chemical method (Purple Stuff followed by lye/water) works well as the lye solution immediately started taking away the remaining anodizing.
