you cannot use this site, becouse the values changes on dual miner
ex:
ETH + DCR = 28 ETH + 600MHZ DCR
ETH + SIA = 25 ETH + xxxx SIA
Etc..
You can, and should absolutely use this site.
You determine the mining intensity using -dcri (for Claymore)
You also have to take into account that dual mining takes significantly more power
Dual mining also increases the fee, if using Claymore