If it was me I would try cleaning it out first, you don't have much to loose. You have a few options. I would change the oil and filter with 10-30, what ever brand is on sale and use a quart of engine flush just follow the directions. You may want to do it twice about a month apart. Quite often new oil will clean an engine pretty good.
A safer way would be to use Auto Rx, Its a mild cleaner that works over a few thousand miles and this stuff works great!