We've got interested in using a chastity device on me (the male), but we don't know which one. We are living in a long distance relationship and we, in the future, intend to use the chastity on me between our meetings. Of course we'd start trying over a couple of hours in order to get used to it and thern extend the time.
So, what we're searching for is a comfortable chastity device, possible to wear under the pants, easy to clean and safely in place.
Do you have any advice? We would be grateful for all answers.
I have a CB6000. I have only worn it for a few days at a time but I only took it off to go to work not because of problems. It is sometimes difficult at night. I never realised how much of a night I spend erect or trying to be! Lots of people seem to graduate to a metal device because they have thinner rings but not sure as never tried one. Do LH have a chastity help page? They seem to for most things. I would start slowly. Don't just lock it on and give your OH the key just before a flight!
I know it might be against the spirit of the thing but if she is going away some time, I would get a duplicate key cut just in case of emergency and hide it somewhere. She doesn't have to know 
People put a spare key frozen in a block of ice or in a box locked with a security code. That way release is possible but the key holder will know. Also they have plastic locks with unique numbers on. They can be cut easily but again, she will know!
We have been playing with chastity for some years now. We started with the CB range and have now moved on to the metal ones for various reasons.
The CB was really nice, a snug fit and discreet under clothes but we found that it was difficult to keep clean and hygenic when worn for several days at a time. The only solution was to be let out each day for washing my bits & the cage. That wasn't very satisfactory for us and inpractical for your situation.
So we moved on to the Fetish Fantasy Extreme Cock Cage. We love this - it is open enough to keep clean, small enough to be worn every day and tight enough to let me know that she's in charge! It is a bit difficult at night though when the nocturnal wood rises and it takes some time to get used to this (and some distrubed nights) so then we moved on to the...
Fetish Fantasy Extreme Prisioner Cock cage. This is great for night time wear as any erection is easily catered for and thus a better nights sleep is had. It is ok too for everyday wear but it isn't as tight so you don't get the erotic thrill of having your erection stiffled. The other advantage is that she finds it easier to tease me through the bars without taking it off!
I tend now to wear the short cage in the day and the long one at night, but as my OH is away all next week for work I'll be locked in the long one all the time.
Also the key - you should always have a spare. We have ours in an envelope that she's signed across the flap so she'll know if I've opened it.
My OH wears the key on a necklace or her anklet and whilst she wasn't sure about the whole chastity thing at first she loves it now.