I did pu/pd (or rather lay down) with dd who was a screaming non-sleeping nihtmare for 6 months, and it does definitely work, but you have to stick with it.
When he stands up, go in, lay him down,facing away from you (no eye contact), pat him once and say night night time or something, and leave room. He will scream.
Go back in and repeat, until he stays down and settles and he will. You may have to go in a lot of times. First time we did it with dd, she yelled for 2 hours, but it did improve.
It took 2 weeks to change her behaviour, eg not screaming out, when she stood up, and a further week until she started sleeping properly.
BUT, it worked. Accept that you will have times when he appears to regress, and that it may take longer than the expected 2 weeks (dd is a vey determined young lady) However it may only take a few nights for your ds
HTH BTW, taking her into our bed was not an option, she would get really giddy and behave like it was party time