From my childhood in Kent, (S/E UK) a common phrase was “S/he can’t X for toffee” where X was the activity of the moment – substitute almost any verb! I haven’t yet done exhaustive searches but find it’s well represented on right-pond references:

can't do sth for toffee British, informal

if you say that someone can't do something for toffee, you mean that they are extremely bad at doing that thing
Annie couldn't act for toffee, but she still got a part in the school play.

(from Cambridge International Dictionary of Idioms)

http://dictionary.cambridge.org/define.asp?key=83528&dict=CALD


Toffee’s AHD entry gives: ETYMOLOGY: Alteration of taffy

taffy

SYLLABICATION: taf•fy
PRONUNCIATION: tafe (with diacritics missing)
NOUN: Inflected forms: pl. taf•fies
1. A sweet, chewy candy of molasses or brown sugar boiled until very thick and then pulled with the hands or by machine until the candy is glossy and holds its shape. 2. Informal Flattery.
ETYMOLOGY: Origin unknown.

http://www.bartleby.com/61/77/T0247700.html


So if anyone has any comments on this phrase’s currency where you live, or any information on its origins....

I'd be flattered to hear from you!