My horse picked out every piece of it and wouldn't eat it!
IMHO a little oil would have much the same effect and it would work out MUCH cheaper.
If oil is introduced slowly, a few drips at a time, built up to the quantity you want to feed... you should have no problems getting the horse to eat it.
If you feed lots of oil (over 1/4 a pint) for an average horse) you need to think about suplementing selenium.
The americans have done lots of research on feeding oil. Horses with certain conditions are fed VAST quantities. Studies have shown that feeding oil rather than grains is healthy for all horses, not just those with a medical need for it. It is all explained on Rural Heritage. About half way down the page they discuss the benifits of feeding oil to 'normal' horses. http://www.ruralheritage.com/vet_clinic/epsm.htm
I used it for a while with no signs of fizziness but I did think it was over-priced and have now ditched it in favour of oil. Much cheaper and his coat is beautifully shiney.
I'm feeding it at the moment instead of a normal concentrate - so works out much cheaper. Definitely no fizziness - and one of mine fizzes up really easily - and both my neds look in great condition. One of the Jack Russell's on the yard loves eating it too!
I fed it to my old horse that used to fizz up at the slightest sniff of most things. Gave him the energy he needed and kept weight on him without any fizzing.
I also feed it to my new lad with exactely the same result.
I've fed it to my WB since early summer this year - no sign of fizziness and it helps keep the weight on him (he drops weight v.easily). Had comments all year about the good condition of his coat and when my instructor clipped him she said what good condition he was in compared to last year.
I just like the fact you can reduce/increase the amount you give easily depending on if you want it for poor condition or weight gain.
I tried it on a ex racehorse i had who came to me like a walking skeleton, I didnt feel that it was working for him and stopped using it after a three or four week period, I cant honestly say I dont think the feed works but i know it definately didnt work on this horse, he had major insanity issues, and worried every single ounce of weight off. I would maybe try it again although i also think it is over priced and much prefer soya oil.