Late Teching... How exactly do you perform it?

Just wondering how someone consistently techs throws,

it seems too fast for me to do it on reaction cuz to me its not too obvious visually that you’re getting thrown until its too late to tech (maybe i should play more tekken lol)

i know in interviews justin wong says he Option select throw techs like he push blocks in Marvel. but i seem to get the low short coming out and then getting thrown before the short hits

or do you guys hit the OS throw tech during your block stun after you confirm that you blocked an attack?
let me know how you guys do it

So basically you want to block a move and then hit cr.lp+lk as late as possible in the block stun so that a will not come out, and then keep pressing it as you would if the other person continued their block string. If they do for a throw since you are imputing the command late you will get a tech. If you input it early a will come out and get thrown.