Powder for daily maintenance but for a crisis or for a known stress event coming up, I'd recommend the liquid. The tube is best if you have a fussy eater - it is administered like a wormer. If your horse is less picky, the liquid dolloped into a feed is fine. Sunny can be picky so I have kept the old Coligone tube and I refill that from the liquid. If administering like a wormer, you do need to have lightning reflexes as there's nothing quite like a sleeve full of sticky aniseed to put you off horses forever!
Coligone powder works out at about 55p per day on a maintenance dose (after a few days loading dose). I keep the liquid for one off's like colic, stressy loaders, competitions or if the horse just doesnt seem right.