Hi there, I don't think you can argue that carrying an ad' is the same as endorsing a product. (And if it is we should be charging a lot more!) You don't watch television and think that every ad' you see is endorsed by, say, Channel 4, do you? Anyhow, to quote Justine from another thread:
"The way our advertising works is that we outsource most of it (though there are some folks who approach us directly) to an agency. Our agency handles all advertisers who come via media planners etc. Our agency has a list of banned advertisers/ products. On it are the following:
Nestle, Macdonalds, formula milk products, political parties, pawn, red top newspapers, plastic surgery ads...
... I guess the only way to be purer than pure is to not accept any advertising at all - but sadly we have running costs and we don't think asking folk to pay to use Mumsnet is viable..."
Fwiw, I know parents who use Lyclear and swear by it. That said, the two times DS has had lice I've used a different product. It's up to you whether or not you believe the claims any advert makes; you look at the options and make your choice - but it is your choice.