Answer: I didn't know you were keeping track of the questions! We're happy to have you visit any time. As for stupid questions - there are no stupid questions! Coating bermuda grass with gasoline will certainly kill it, but it will kill other things it comes in contact with, as well. I'd also be concerned about vapors and contamination of the soil, and rainfall or water from the hose floating the residue all over the yard (to say nothing of the possiblity of combustion!).
Around the garden I use Round-up to keep the Bermuda grass at bay. This works great in the late summer and early fall. (Roundup has an inaccurate reputation as a warm season pesticide but I have killed bermudagrass well into October.) It is a contact herbicide so you'll want to paint it on the mound of grass (or take the bottom out of a cardboard box and set the box over the clump of grass and then spray it).
As for preventing the pesky grass from coming up all over the bed, try using several thicknesses of newspapers on the soil surface, and covering them with an organic mulch. The newspapers will effectively shade the soil to suppress weeds and will break down in a couple of years. You can incorporate the mulch and the newspapers into the soil to nourish it, and then replace the newspapers and organic mulch with fresh stuff.
Hope this helps keep your shrub bed weed free.
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