I just took a 3" ID piece of tube, cut it down to about six inches, threaded one end, drilled a hole in the can, welded a bolt to the inside, then restriction fitted a slightly smaller piece of tube inside the main tube, put a tension spring on the top side and fitted it to a piece of sheet steel on a small hinge. That way I can dump liquid in, but it stays closed unless it is being pressed down by the marinade. Kind of like a down hole safety valve.
"It is not the critic who counts, nor the man who points out how the strong man stumbles or where the doer of deeds could have done better. The credit belongs to the man who is actually in the arena, whose face is marred by dust and sweat and blood, who knows great enthusiasm, great devotion, and the triumph of achievement, and who, at worst, if he fails at least fails whilst daring greatly, so that his place shall never be with those odd and timid souls who know neither victory nor defeat. You've never lived until you've almost died. For those who have had to fight for it life has truly a flavour the protected shall never know."