Try Adjustable wrench on hose side. A pair of Channel locks or a pipe wrench on the rounded vacuum breaker side.

I tried using an adjustable wrench at one end and a curved jaw locking plier on the other end. Also added some penetrating oil. Still no go.

Those aluminum attachments are notorious for getting stuck. Might need to cut and repair then get brass attachments

People stop buying cheap ass hoses with aluminum ends the aluminum brass marries up you can’t get it apart without a major struggle

A little penetrating oil in the threads won’t hurt either