Thanks for all the help. I have been looking for an excuse to scoop up a bottle of rubbing alcohol, at least one that doesn't involve me invoking lumbago to myself and the other ailments of the ancient
On clothes you also try the iron with a rag between it and the clothes in question - it melts the stuff from the cloths to the rag
(this has worked for wax - so why not resin?)
I just wanted to report that I removed pine tar from my tent after the moot using a warm iron over some kitchen paper until the majority of the resin was off the fabric and absorbed by the paper and then wiped the rest away with a cotton wool pad dipped in ethanol. It left no trace of resin whatsoever. Job done.