Thanks for the suggestion but I've tried both with no real success.
I serve crackers, cheese and a few other bits but nothing very strong flavoured.
It doesn't fail drastically until the 10th or 12th beer sample so maybe that's normal. When I say fail I can still taste the beer, I just lose out on the subtleties, so I tend to serve bigger, bolder beers at this stage.
They best thing I have come across so far is beer like Rodenbach Grand Cru or even something Gueuze-ish, which revitalises it for a while.
I just thought I might be missing a trick.