I have never used coco, I've seen good grows in it though.. it all boils down to how well you can use 'your method.' Nothing works for everybody and everything works for somebody, are you driftin' my catch? I just wanted to mention that lots of people wash/reuse their perlite. Perlite has been used for years and years to successfully grow pot, there may be better stuff out there now but it still has it's place, at the very least- in history. I use perlite, but again I'm not a coco grower. I like the advantages coco has to offer, but if your method already works for you then there's no reason to change it.
The purpose of perlite is to add air/oxygen to the soil & to improve drainage. Even completely soaked coco coir is too-wet, that would be the only way I could see perlite being of any benefit to coco coir... you may have to water even more frequently but ideally you want your growing media to be 50% moisture and 50% air as often as possible.