I didn't try to dual mining for a while, what coins are profitable these days as secondary?
There are none, since most of the dual mineable coins are basically GPU compute there was an ASIC released pretty much for all of them.
Even if you are mining at work and got free power its not even worth it then because each GPU will consume about 30-40 watts more power and will run hotter and emit much more heat. Not worth it to make a few pennies a day.
Back in June 2017, you could of made over $2 alone on SC just by dual mining it, not including the $7 daily ETH profits.