Can using too high a concentration of salt solution damage FUE grafts?

It is best to ask your surgeon about post operative care as each doctor has their unique regimen.  There is no need to use a salt solution.

The recipient area requires daily washes as well to keep the recipient area free of crusts immediately on the first day after the surgery. Once the crusts are off and remain off for 2-3 days, there is no more crusting present. Keeping crust and scabs on your head for long periods of time raise your risk of infection. The recipient area requires daily washes as well to keep the recipient area free of crusts. I generally recommend the use of a sponge and supply my patient with a surgical sponge to fill with soapy water and press on the recipient area daily. By repeating this daily, all crusts can be washed off without any fear of losing grafts. IF any crust is present, use a Q tip and dip it into soapy water, and roll it on the crusts and that will lift them off without dislodging them, but never rub them, just roll the Q tip on the recipient crust. I like to see no evidence of any crusting in the recipient area and the crusts from the donor area gone in 3-4 days with daily washing. To get the crusting off, you need to leave the shampoo on your hair for 10 minutes and as the crust become water logged, then will come off with gentle finger action. Repeat this twice a day until it is all
gone.The application of a higher concentration of salt solution probably had little impact on the grafts