The Wyoming solution to everything will work!

Seriously, those things are near impossible to get off and especially from something like stucco without really doing damage to it. I hate to say it but get what you can off before you compromise the stucco. Then see what things will look like priming and painting over them?

 

Muriatic acid will soften them somewhat.
I managed to remove some from brick with a strong acid solution and high pressure water jetting. I don't know that stucco would withstand the pressure without damage.

There is no 'trick' that I know of that will remove them easily. Generally they will pull pieces of the substrate off with them no matter what you do.

Muriatic acid is dangerous to work with.

 

Muriatic acid is dangerous to work with.

For sure! Wear protective clothing including acid resistant gloves, goggles and an aspirator with a suitable cartridge. Be especially careful when you spray it after with a pressure washer. Even dilluted it can burn.

 

Good grief. I may try the torch. Will report.

 

You might try cryogenic pellets and dry ice blasting but again I worry about damage to the stucco. And if you rent equipment, you will need thermal gloves and clothing protection or the extreme cold can damage your skin. The CO2 is harmless enough though. It is a great process for removing paint from brick and textured surfaces. Might work well for your application.

You can rent the equipment and then buy the pellets.

 

I used a propane torch to remove them from brick. It may work OK if you are careful to keep the flame moving and don't over heat the stucco. Make several passes instead of trying to get it in one shot.