Block stutter, is it ok to replace words or force the difficult words out?

Block stutter, is it ok to replace words or force the difficult words out? I have read that it's better to try and force difficult words out instead of replacing them with a similar word. Well sometimes I have to reword my whole sentence and it doesn't even make sense anymore! I have tried forcing difficult words out but I physically can't do it. Then people just look at me like I'm crazy. If anyone has any tips on how to force a blocked word please let me know. As a side note it's not always possible to replace words and then I'm in trouble! Edit: few days later, I was not expecting so many replies, thanks. Thank you everyone