Hi biometric
Currently, there is no way to delete those entries from the jOpenSim admin side ... allthough I have planned to add more features including this for the search admin in a future version.
If you have spam problems, currently you only have the possibility to delete those entries directly in the database (e.g. with phpMyAdmin).
You will find those entries in the tables starting with #_opensim_search_... (where #_ is your Joomla db prefix). The only one you should not change is #_opensim_search_options, which is responsible for your search settings. All others contain the data that will be returned in case of a search. So if you delete something in there it will immediately be removed in the search results.
I hope this helps
Greetz
FoTo50