Is there any value to the code in failed attempts or do you just want a log of things you have tried? If the former, you could try a single experiment branch a

Is there any value to the code in failed attempts or do you just want a log of things you have tried? If the former, you could try a single experiment branch and use tags to denote different experiments. Add a tag when you finish an experiment then overwrite with your changes for next experiment and repeat. This would keep all the changes while not have having a huge number of dead branches and the branch could be merged when necessary. If the latter, why not an experiment log that is checked in which has a similar form to a change log? Or maybe create an issue and branch for each experiment then update the issue with results and delete the branch?