This is bad advice. All this does is is flag the number as in service and it will get even more calls.
Aside from the advice I gave in another set of comments, you could and should check with your cell provider and turn on spam blocking if they offer it.
I have a total of 5 numbers across 2 phones, 2 at GV and 1 at textnow. I get very very few spam calls and texts. I very rarely answer the phone for a number I don’t recognize, I let it go to vm and then if it’s legit and important I’ll consider calling them back. I keep my phone on silent and all calls and notifications go through my watch so I am not listening to the phone ring especially when I am working.