rec.gardens
*.diy
You actually want to add a trace of copper sulphate to the bare stump first to deactivate the enzymes that protect fresh wood from fungal attack. Use too much and it will delay rotting. And some nitrate fertiliser or ammonium sulphamate in drill holes will accelerate the natural decay process.
In the UK the sulphamate product was sold as RootOut at one time.
(unlicensed use these days - due to worries over honey fungus)
Regards, Martin Brown