Dollar Tree sells a variety of hand soap. I found Softsoap refill bottles for $1.00. After a $0.10 MobiSave cash-back offer pay only $0.90!
Have you tried MobiSave yet? Once you submit your receipt, they add money to your PayPal account on the same day.
Also save on Softsoap 5.5-ounce pump bottles or Dial Hand Soap 7.5-ounce bottles: