You need to separate out Hexes/Curses/Spells vs Entities. And then see if Servitors handle these two categories?
The Servitors should be able to remove hexes and curses - as Sammy rightly pointed out, while we think every one is getting cursed or spelled left and right, that is not really the case.
The extent of protection - Spell/Curse Removal audio vs Servitors - servitors should be able to learn and adapt a lot of skills, so, in my personal opinion, your Servitors should be able to do a whole lot of things here. So, with just the servitors, you may very well be good - in the case of curses, hexes and spells specifically.
Second part - as for removing and de-patterning malicious entities (we are talking strong, intelligent ones here), like what the De-Inhabiter does, I am not too sure Servitors can always handle that. I would let @Dreamweaver comment on that here. Probably the servitors can handle some of the entities, but stronger, inter-dimensional ones - not sure. Servitors can learn a lot of things, but they also have limits on the size of concepts they can hold and operate.
Also, the technology used in the De-Inhabitor audio is pretty unique, not something generally known to most folks on this earth. 
(I will shut up here as my expertise on this tech is next to nothing, Captain and OM are way more qualified to comment on that aspect).