Why don't you use source control instead. Don't say who you are in the comments, that's what "blame" is for. Don't comment code, delete it, it won't be lost since you have a history. Make a branch for your experiments if you have to. The state of your work should be apparent in the bugtracker.

Code comments are code comments. If you use comments to help with your development process, there is probably some work to do with your toolchain. Good source control and a bugtracker are a must.