My Nephew years ago had an old 190D and he did a similar trick to his oil pan. He called and I went to fix it in the parking lot of the Mall. I used JB weld and washed and scrubed it real well with a degreaser and a nail brush The hole was about a quarter size with a crack about 3 inches along the seem. As he left the oil all over the parking lot I put kitty litter on it.
I let it sit over night came back in the morning and put new oil in it and he drove it for 3 years after that until he was rear ended and it was written off. It made an ugly mess and trying to smooth it with water made things better as it dried. So I would give it a try....and watch your pan every now and againfor staining. just my 2 cents