I agree on replacing the freeze plug. I have had to do this on several vehicles in the past and it's not a difficult job, often times accessing it easily is the most difficult aspect.
If you feel you need an immediate solution, you aren't confident in your ability to replace it, etc. You can try one of the many products available at any auto parts store that are made to seal head gasket, water pump seal, etc. leaks like Blue Devil, Bars Leaks, etc. I have actually had very good luck with these types of products on automotive leaks. I am generally not an advocate or believer in "miracle" or "easy" fix products.....I think a lot of them are B.S. but have to admit that I have felt forced to try several quick fix coolant leak products in the past and surprisingly they worked so well I never had to go back and make what I generally would consider to be a proper "permanent" repair/replacement.