Pruning a Yucca by chopping the trunk in half!!

Hi,

as from my previous thread, I've got a Yucca that's very deformed. I posted a question about lopping off the deformed branches, and I had a mixed bag of answers. Then I came acaross the link below:

http://www.gardeningknowhow.com/indo...ng-a-yucca.htm

I notice that the top of my Yucca has brown wax seal. It seems like I don't have much to loose by trying the pruning technique as suggested below, but I wondered if I should re-seal the top of the bottom branch, and if so, can anyone recommend what I should seal it with?

Anyone know why they are sealed? Is it to prevent branches sprouting out the top?

Thanks for your help!

Cheers,

Tom