That's the one..
I bought it from B&M, went back, none on the shelf.
Walked the full length of the store to find a staff member, asked her if they had any in the storeroom, even showed her a picture of the said tub..
I said, "there's none on the shelf".
"I know where that is, follow me, she replied"
We walked the full length of the store to the empty shelf, she looked at me and said.. "we haven't got any"!
I did count to 10 before telling her thanks for checking for me..
Anyway found it in B&Q, bought 2 more tubs, just need to get myself motivated for the final push tomorrow..