The Author (D. Richard Hipp) of SQLite uses Tcl extensively. I think that is a much better recommendation than "stay away". Use what you LIKE.
I think many people have trouble with TCL because it looks a lot like C and so they expect it to behave roughly like C. But TCL is a fundamentally different language. It is better to think of TCL as LISP with C-like syntax. Once you grok this difference, TCL becomes a very elegant language.