Question
i have some tree stumps and want to prevent bugs infesting them. i had heard about a solution of half mouthwash and half of another liquid. it is suppose to keep out bugs & disease from the stump and seal it. thank you, Mary

Answer
Insect and fungi that infest cut stumps are part of nature to speed up the decay process. The products you mentioned will not control or prevent these. I would not want to since the insects and fungi will help remove the stump. If you want the stump gone fast then the best way is have the stumps ground up using a grinder.   

The organisms that rot or decay wood are called fungi. Fungi do not possess chlorophyll and consequently must derive food from other sources such as wood stumps. For fungi to live and grow, they must have the proper temperature, moisture, oxygen and food conditions. Food is supplied by the stump or wood, and oxygen is supplied by contact with the atmosphere. For optimum fungal growth, the temperature should range from 50 to 90 degrees F. The wood moisture content should be approximately 20 percent to slightly higher, but not water soaked. These optimum conditions do not exist for long periods, thus stump rotting actually occurs intermittantly and decay of the entire stump is a long-term process.

To enhance decay conditions, the stump should be cut as near ground level as possible, covered with sod and kept moist. If possible, several large holes at least 1 inch in diameter should be bored vertically into the stump. These holes expose more wood and slightly hasten decay. During the first year following tree removal, the organisms that decay the wood tend to be nitrogen-limited. That means that the addition of fertilizer during the first year, especially a high nitrogen fertilizer, will hasten decay. Be careful not to add so much as to cause a fertilizer 揵urn?to surrounding plants.

The organisms that come along to decay the stump after the first year or so tend to be carbon-limited. That means that adding high nitrogen fertilizer no longer hastens the decay. The alternative is to add carbons (in the form of sugar) to the wood after the first year. Simply add some ordinary granulated sugar through those holes and the process will speed up considerably. Keep in mind that the heartwood of some species such as cedar, mulberry, bois d抋rc and locust are naturally durable and will take much longer to decay than softer woods.

As the stump rots, depressions or holes will develop. These can be unsightly and a hazard. You can re-fill these depressions with topsoil as they develop.