What if you forget your duct tape?
The physics is actually pretty simple:
It doesn't work.
Even if you decide to ignore the whole pendulum effect of 165 lbs 25 feet away from 900 lbs of ballast, consider the forces at play:
Yes, your masts resists some pretty serious inputs while sailing.
BUT, those inputs are not concentrated at the top 25% of the mast. in fact, just the opposite, the max input is to the lower 50%.
Below the shrouds.
Below the forestay.
Further, have you calculated how long it will take you to be winched up the mast, then down the mast, compared to gin-poling the mast and restepping?
Oh yeah,and once you are at the top, what if it ISN'T a bulb, but a bad wire?
It is a whole ton easier, faster, safer and more effective to drop the mast.