YES CLEAN IT OUT...Like Berry said pull the tin shields off and plug the holes under the shields, wads of paper towels, and lay the engine on its side. and pour some cleaner ?? solvint, deasel, 409, paint thinner, in that side, let it soak, what two three days?? then lay it on the other side, and soak again .... and then a pressure washer in the area. Both sides, I assume the pan is off and clean, also. yes I would wash in the lower end as well. Now there is going to be same lose stuff, in and around the inside, blow some air in and around, you will have some water left in where you don't want it, so when its running again, get warn and change the oil soon, and the filter if you have one. Get it warm again and check the oil dip-stick, looking for small water spots, You deside its running so good now, change the oil again, up to you ??
AND::: The oil pump pich-up screen, a good spot to clean, don't be afread to soak it and set it on fire... OLD....BILL