Cyclomethicone IS cyclopentasiloxane, and also cyclotetrasiloxane (just a smaller molecule). It's just another name for the same thing! Neither will build up on your hair, although they are not water soluble. The reason for this is that they evaporate. They do not remain on your hair. You need nothing to remove them because they do not remain on your hair. I know I have addressed this in an article, but it is still a huge point of confusion for folks.
The reason some find it makes their hair feel bad is that when it evaporates it can make your hair a tad dry and maybe mess with your cuticle layer a bit, just like alcohols that evaporate.
Also, according to all the research I have seen, all of the silicones can be removed just as efficiently by products containing cocamidopropyl betaine or coco betaine as by SLS or SLES.