My solution for this is a script that commits all my changes then tags the resulting commit with a basic descriptive name. Something like this:

    git discard bad-idea-didnt-work

Which creates a tag discarded-bad-idea-didnt-work, then resets back to the previous commit.

I can still find and rescue the changes later by looking at my tags.

Others have suggested using the stash for this but I prefer to keep my stash stack free for shorter-term contexts, eg. if I'm halfway through something but need to go checkout another branch briefly.