I cannot imagine how that would work. If you already know that you are an okay person or a handsome person you might believe it when others say it. But if you don't have high self esteem, such words are at best comforting lies, told by people who (according to your internal voice) think you are too stupid to recognise that they are lying, or at worst they are pure mockery.

Having low self-esteem is not the same as secretly thinking that you're a good person but pretending that you're not. It's knowing that you are worthless, uninteresting, unlovable. Other people can tell you otherwise until the cows come home (and then they can tell the cows) but you don't believe them and the words do not comfort you, much less convince you.

This is perhaps not true for everybody with low self-esteem (heck, maybe it only applies to me - I usually don't know what other people think or feel) but all the same, no, it is not appropriate for a T to spout compliments indiscriminately, to a client who feels uncomfortable about such compliments - as the OP did. Much better for the T to use facts, such as the fact that attraction is not based on looks alone.