Hello Mfumu,
Yes, it works and people do get PR with the private sponsorship. I lived in Nairobi for a while and I witnesses a lot of my friends beiing privately sponsored and they all got their PR after all.
CIC is know for having a huge backlog that create all the delays and causes frustrations but you will eventually hear from them.
Just be patient, mokonzi...
Un jour ou l'autre...