Epsom Salts is magnesium something (can you tell I'm a Realtor & not a chemist???).

Dead Sea salt is sodium.

Sodium kills.

The sodium in Dead Sea salt is bad enough but the chloride content will kill your roses. Roses are sufficiently sensitive to chloride that in some cities the chloride added by water softeners will turn the leaf tips brown when tap water is sprayed on the foliage. I would not use any fertilizer, organic or otherwise, with a chloride content of 1% or above. Dead Sea Salt is probably close to 50% chloride.

Taking Dead Sea salts is not good for the Dead Sea, either. I'd stick with the Epsom salts for both the bath and the roses.

Here is a link that might be useful: Israel and Jordan launch global campaign to save the Dead Sea