It takes a few day (5 days) before they try, according to my source dive... Which, assuming you have good psychology potential, is too much for them to escape before beeing converted.
And it also depends on Agility, Intelligence, Strengh, and number of interrogators.
As for suicide, if they have at least 2 (or maybe 3) heart, you're safe. Besides, unless you beat them up, they only try that option after one week of captivity.
Also, one thing I forgot: more interrogators = more effective.
To those who were wondering: your lead interrogator makes an attack roll, which is basically: Number of interrogators + day spend in captivity + highest business, science and religion of your boys + psychology roll for the lead interrogator + heart attribute roll for the lead interrogator - 2*(wisdom roll) for the interrogator + 5 if the target is not tied up + 10 for expensive props + 10 + armor drug bonus for drugs. If the attack roll is 6 times higher than the target's wisdom roll (1D6 for 3 points of wisdom, 1D3 if there is an extra point, 1D5 if there are 2 extra points, 3 highest dice taken), then it's a success, and the target is gains 1 heart and looses as much juice as the attack rol result.
There is a little thing of note: you get a second attack done, highest Heart from the interrogators + twice the highest psychology skill from the pool + the highest armor interrogation bonus - the highest wisdom of the party. If this attack is higher than the previously described attack roll, they take this one as the true attack roll against the wisdom roll.
Also, if the target has a higher Science/Religion/Business than your interrogation pool Science/Business/Religion + psychology AND you're not using drugs, it's useless to even try to sway them to Liberalism.
Yeah. That's pretty much it.