I'm not sure about OTC companies, but one of my other investments recently approved a share buyback and it really didn't have an effect on the stock price. Although that is a NYSE company and they are trading in the $70s pps. OTC is just a whole different animal and is filled with traders that do not act like your NYSE, NASDAQ, etc. traders, so who knows what effect it would have if any.
Also, why does this RS talk keep being brought up? It has been discuss ad nauseam. There is no RS, there is no dilution. Stop with the fear mongering.