If you should release your sperm on a rag and later re-insert it into the vagina, can it result in pregnancy?

Almost 100% NO. 1) sperm released on arag will die very rapidly. 2) sperm need to be introduced well into vagina in order to reach the cervix. 3)sperm need to have semen for sustenance ; together with vaginal secretions as a medium for swimming through the cervix before passing through the uterus and into fallopian tubes where fertilization takes place. 4) semen will likely have been absorbed by a rag.
Chances of pregnancy. Yes. Even after ejaculation, there are still sperm and ejaculate present within the urinary tract of the penis.