Oh 3.2.5...
If it's not too much of a problem to rewrite queries, you can backfit the openacs 4 db api to 3.2.5. I know there are several versions of the openacs 4 db api ported to 3.2.5 floating around (search the bboards). If not, there's no easy way to do it from tcl, unless you somehow keep track of all the handles that have been allocated, which is what the oacs 4 db api does.
If you want to write a tcl extension in 'c', then you could also create a proc for closing all of the handles in the current connection thread. Db handles are stored in thread-specific data, so it's easy to get access to them from a 'c'-function.
