The first time I went fishing at Rocky Point brought a bag of anchovies I'd bought in a convenience store in Bullhead City. I didn't really likr them because they semed to fall apart a lot. I quit using them and bought bait locally. A few years later, Don from this forum mentioned using anchovies for corvina bait. I pretty muh alleviated the fragility problem. When I buy a 1 lb. bag of frozen anchovies I throw 1/4 to 1/2 a cuo of salt in and mix it up good. As the salt d4raws the moisture from the skin through osmosis. The skin toughrns up. It works well with shrimp and calamari too. I've made multiple catches off off the same piece of bait. Yhat inctreses your fishing time which is important.
Through the head or back doisn't seem to make much difference. sometimes I'll use two hooks through the head and back. I dson't really measure the salt. I just pour what looks like the right amount in my hand. Sea salt might be better, but I just use Morton's iodized table salt. It's cheaper.