Schards#2 For worst all round experience rather than worst performance (but incorporating a terrible performance) i'd go with Rochdale away circa 1980.
In those days we used to take two coaches at most to away games up north many of whom were women or pensioners, therefore, there were only a handful of young males that were considered legitimate targets by the rougher home fans. There was no segregation and we were spat at and intimidated by 10-20 Rochdale fans all game which we lost 4-1 in pissing rain. Followed by a life endangering unescorted walk back to the coach which was hit by a stone on the way out of town.
I do wonder how some of our younger gobby contingent would have got on in those days.
Sounds like a fascinating day out. Its amazing how far we've come, and how filthy some clubs were back then. Macclesfield hardly had any fans when we went there, but for most detestable I've seen, I would have to go for Wolves and Burnley. Anyone remember that 2002 game . We won 5-2 by my god were they a horrible little club, living in a horrible little town. Dont think it beats your Rochdale story though