i've had this thought before (well similar) and i think the problem is valve never used something like this, so they didnt put any blatantly obvious entities in for it, but it doesn't mean it's not possible, you could spend hours testing entities to see what happens, and find that it's impossible, or you could give in gracefully and use something else to do what you want, i made a set of charges on a wall wired to an explosive trigger thingy like they use to blow up buildings etc, all the ct had to do was turn up and press the button, and the wall literally blew the fuck up!
this means you can't have a single ct do it, but when you think about it, cs is a team based game, so everyone should be able to do everything, just because you never know what kind of morons are on your team.. =/