I'm trying to cut down on the number of containers I have for different cleaners. When I was at school, the domestic science teacher told us to use washing powder for washing dishes. I thought this was very odd at the time, but recently I've used bio laundry liquid to wash dishes, and it seems to do a better job than washing-up liquid. But the bio stuff is quite harsh if it gets onto my skin, and it makes me wonder if it's really safe on stuff that will come into contact with food (eg plastic containers, that I understand can be a bit porous and maybe retain a bit of what they're washed in)?