FA doesnt say to do any action like do push up 20 time after prayer, you will get reward for this weak hadith! its about an action which has been introduced via weak hadith, and not the amount of the virtue. in FA all weak hadith are related with sahih hadith and only differes amount of virtue, and not introducing any specific action like kiss this and wipe that. this is related wit fiqh, and no action is allowed which is based upon weak hadith. which is already cleared by bro abuhajira.