Thanks for the tips

Unfortunately we didn't have time to really scrub and dry the boots again before they had to be packed away (We're flying to Canada today), so it's been a case of bag them and and hope for the best. Will definitely give bicarb a go next time, and have a vat of Febreeze handy.
Also, the treacle dispersed over time, so I was saved from having to stick the hand in, good to know there is an emergency speed solution too though
Probably the last post for a little while, until we're using a private computer out there anyway, so everyone keep well. Also, Bill, if you catch this, drop us an email to let us know how the editing goes, but don't attach pictures if you don't mind, we'll be using public PCs for a while!
Jon