Mine was like that when I brought it home a couple years ago, wrong oil and lucky no damage noted. What I did was disconnect the oil filter (oil strainer) and drain the contents of the oil tank into a clean catch can (large soda bottle). Then I raised up the end of the oil hose above the oil tank and poured a little gasoline into the oil tank and blew backwards into the oil line to agitate the contents by the motion of gasoline and air.
Then again drained the mixture of gasoline and outboard oil into another clean catch tank (large soda bottle) and dumped that into my riding lawn mower gasoline tank (some say never burn 2-stroke premix in your lawnmower, not sure why?). Then made sure all of the liquid had completely drained from the oil tank and line.
To eliminate a possibility of residual contamination, I poured a bit of XPS2 through the oil tank and lines to flush out the remaining gasoline soup, reconnected everything, put a few quarts of XPS2 in the oil tank, purged out the air bubbles using the bleeder screw on the oil pump (don't over tighten this bleeder screw it can break off) and went for a ride immediately, to confirm the oiling system remnants of the outboard oil were purged out and through the injection pump and lines, not allowing any time for any remnants of the two oils to fester and congeal.
So this process worked fine for my case, not sure how it works out for you...
If you're not sure the oil injection is working (for the time being) and this ski is carbed, you can remove and replace the contents of the fuel tank with a few gallons of pre-mix in the fuel tank. Then once injection is confirmed working, fill the fuel tank remaining capacity with fresh fuel.