"Spam Results" from search engine

Add-ons
#1

Two additions to my favourite search engine make many searches a chore. Both Pinterest and Quora are considered spam by me and like Wiki are just not reliable since they are unauthenticated sources od mob rule information.

If I use Chrome I can add the modifier “-site:quora." or "-site:pinterest.” automatically to Google to eliminate it from my search results.permanently

Is there any way to do this automatically in Firefox with the default search engine or is it possible to create an addon that will do the work for me so that I don’t have to add it each time.

TIA

SM

#2

It shouldn’t be hard to create an add-on that does that. It just needs to listen to requests related to search and modify the search string to add those parameters. There might be extensions that do that already.