I might use them on Cymbidiums, but not on any non-terrestrial.

I've tried them
I dont like them because they can hold water and attract fungus and rot
I find that nutricote, sold commercially as dynamite works best. It is a chemical release fertilizer and releases small doses with each watering.
I dont use Osmocote either as it is a temerature release fert and only releases when temps get to a certain temperature then releases it all at once, which can burn roots and plants