How to use X-Pand-O?

[Davidsonranch]

I've been trying to research and search old posts on the use of fillers and the posts go on and on. Looking at Winning fill, Full Tank but I saw a lot of people recommend X-Pand-O, Expando, whatever?
So is it a right before show day thing or do you start well ahead of a show / fair?
Our fair has horrible stall conditions.  It's hot, very little air flow, we have to use city water which the cattle won't hardly drink, we show outdoor where it is very hot, etc.  Historically calves need "something" extra to fill them out a little as most cut way back or go off feed.
I know what people appear to be using, but want to know "how" to use them as far as rations, when etc.

 

[Imel Show Cattle]

I feed it for a few days before  I show usually. On show day I increase it to 2 pounds or so. About a hour or so  before the calf shows give it a bucket of water. Then let them have another half to full bucket before they go in. Works great for me.

 

[dscott]

we feed it for about 2 weeks then stop for about ten days and replace it with feed then start again for 2 weeks then off for ten and replace with feed so on and so on that way ur strething the stomach then filling then stretching then filling