Unfortunately, there is no alternative to Cyanuric acid. Working without any chlorine stabilizer in a saltwater pool will overwork your salt generator since it will be working at a high percentage and pressure to keep correct levels of free chlorine in your pool water. You just have to find Cyanuric acid for your pool. Alternatively, you can shut your salt generator for some time and use tablet chlorine (has Cyanuric acid) to sanitize your pool, tablet chlorine will deposit Cyanuric acid into your pool then you can put your salt generator on after getting some Cyanuric acid level enough to stabilize your free chlorine. Remember to be very careful when using tablet chlorine since you can't lower the cyanuric acid level unless you drain and refill part of your swimming pool water.