I'm a salty sweater too and can be in agony after exercise. I was suffering so much with cramp even after runs during the day/night I had a sweat test which revealed I had very high levels of salt loss in my sweat.
I started taking rehydration tabs and its generally changed my life! I take a low dose one during days when I am not too active and a higher dose one on more active/sweaty days. (Ive been using H2 Prohydrate)
Ive been using them for about a month now and I havent had cramp once (this is compared to waking up on average 5 times a night and leaping out of bed in agony, constant cramping during the day in my legs and feet and several agonsing, contorting cramp episodes on longer runs!)
All my runs have been better and no cramping what so ever - its a bloody miracle!
I had laser treatment on both thighs and a phlebectomy on both legs from the knee to ankle at the end of November. I was advised to avoid any excercise for 2 weeks only but this was about right as I was quite sore and bruised. Ive been back running and dancing most days since then and its all been fine.