after being told there aren't any chemical etching products for acrylic i was told sanding it would achieve the same affect. my question is what would be the best technique for this? grit/direction/time?
600/small circles/60 seconds. Light pressure would keep from making deep scratches that show up so bad.
It don't take long to scratch up plexi really well (especially when you don't mean to), you can wipe off the dust every-so-often to check the progress.
Practice on a scrap piece of you got one.
Were you making (frosted) flames on your window?
For small detail work, you can try a typing eraser-pencil type. Sounds crazy, but it's an abrasive in a rubber base that's easy to control in tight spots.