Can you use the crockpot to cook boneless pork ribs if you only have 3 hours?

all of the recipes i see for the crockpot or slow cooker say 6-9 hours. usually this isn't a problem, but I only have 3 to 4 hours before dinnertime tonight. I was just going to try cooking them with onions, garlic, brown sugar and apple juice, finishing it with barbeque sauce at the end. will the completely thawed ribs have enough time to cook through?