If you walk up to an npc that is blocking the road ((Bug Catcher Rick) From Viridian Forest) when hes walking toward you, or talking to you, just log out and log back in and now he will be back in his stating spot and will not start walking toward you allowing you to just keep walking past him. If done while battling you Won't be able to go back and battle him again (Acting as the battle had an outcome(win/lose)) and you will be sent to the pokecenter and your Pokemon will be healed(This happens during battles with anything(ex. random encounter, npc battle)).

 

Edit: This also works with the person in 'Pewter City' that blocks you from leaving without battling brock. This one is harder but all u have to do is 'alt F4' (Logging out work too) right after he finishes talking and reopen the game and walk right past.

 

Proof Of NPC Skipping -

Alt F4 Method - https://sendvid.com/0s4qry07

Logout Method - https://sendvid.com/lozem5o4

 

Overiding The Battles Outcome - https://sendvid.com/o37yefdx

Also works on the guards to Saffron City - https://sendvid.com/w9ddtmle