Does this plugin working on my website?

Glad to help. To verify whether or not Blackhole is working properly, you can follow the steps on the Installation page (where it says “Testing”). Also here is a more advanced guide that explains further details about testing, etc.

Also as explained in the documentation, any sort of *page caching* plugin prevents Blackhole from working properly. Here is a guide with more infos.

I hope this helps. Let me know if I can provide any further infos.