I am with jingles. I take great pride in hanging out my washing. I never put whites in with anything else, I think that's half the problem. I use Ariel bio powder and chuck in a sachet of Dr Beckmann Glowhite stain remover. £2.00 for 5 sachets in Wilko. Put in some nice fabric softener and that's it. Perhaps I am lucky that OH doesn't seem to be bothered about bio powder. All my whites, be it socks, towels or pants look sparkling in the sun on the line. I remember my poor old Nan sweating over a boiler and then using a "blue" in a sock for the final rinse, thank goodness we don't have to do that anymore.