Boots?
Actually I don't think your allowed to take bottles even if they are empty they have to be small bottles, not half empty bottles, its not just the quantity thats the issue, its your ability to mix them together in one container making a compound they are probably worried about. So 2 equal size half empty bottles mixed could be mixed into one bottle which is what their issue is.
Anything above that is not allowed.Thats what I was saying as the OP said he didn't want to take half empty bottles, which would not be possible....
BOOTS is your friends
Your being illegal OP stop it now!
I never understood this liquid thing. I'm convinced it was a money making ploy somehow, or done to put the public at ease (seen to be doing something).
100ml is is more than enough to blow a hole is the fuselage.

Short of finding small 100ml bottles, you can buy airplane-friendly sized shower gels, shampoo, etc in most Superdrug and Boots stores.
I never understood this liquid thing. I'm convinced it was a money making ploy somehow, or done to put the public at ease (seen to be doing something).
100ml is is more than enough to blow a hole is the fuselage.
I can take my leathermen, a locking knife through security every single day and no one bats an eyelid. Take a muller fruit corner and you instantly turn into a member of Al qeada.