Where can you get lye OTC in the UK ?

[ythan]

What is it used for? Are there any brand names SWIM should go for?

 

[geeg30]

You can get it in B&Q. Homebase, maybe even tesco or asda - its sold as drain clearer from the shops. Should be about £2 for 500g. Sodium hydroxide (lye) is sold also for making biodiesel on ebay UK in kilo's

 

[fourthripley]

Caustic soda here. Unblocking drains, scrubbing yards. Homebase, B&Q, pound shop, old fasioned hardware shop. Jeyes Kleenoff super-strenth is good.