Absolutely this!

I briefly worked in a kitchen that made nothing but fried fried food for about a month. Dawn dish soap is easily the best answer here.

I wore the same pants and shirt every day of work, so it would collect about a week's worth of grease and oil. I'd start with handwashing it with Dawn soap. Depending on the amount of soap and grease, I'd generally have to go through the washing and rinsing process about 3x before enough of the grease was removed.
After the third washing and rinsing, I'd use clean water and a bit of fabric softener to finish things up before allowing the clothes to dry.

The fabric softener was largely to give the clothes a clean smell as well as to take advantage of the thin layer that fabric softener adds to clothing.

But yes, Blue Dawn dish soap. And opt to hand wash it. It's easy to add too much soap to a washer resulting in suds foaming out of the lid.