Re:now to try it on Lego pieces (Score 1)

I was bathing grey and white Lego pieces in just hydrogen peroxide and sunlight (outside) in 2005/2006. It took a few hours and worked very well but definitely needed something to speed it up.

The Lego pieces don't seem to have been affected since doing this after just checking the model.

I have used Brasso (liquid) or jeweller's rouge on bricks with fine scratches (build a wall and do a side at a time) to a least get finer lines in the same direction.