Clean My PC Registry Cleaner is a good one. I have never had an issue with it and I use it on my client jobs after my regular workking hours. With regards to the claim that registry cleaners do nothing apparently you must be high on crack because they resolve a lot of issues. Why cleanup your cookies and temp files they are just going to come back again. Because they are there and you don't want them. Why would you want registry entries for programs that have been removed? You wouldn't that's why!
Temp files and cookies are totally different things. These two are known to cause slowdown in web browsing, but a bloated registry's impact is mostly unknown.
Conventional wisdom is you don't need to use a registry cleaner. Chumly isn't the only one against them either, several other people are as well. For example, here
I do recommend the use of registry cleaners when cleaning up malware because there is a possibility of an entry causing a problem, but for the most part, they should not be run frequently.