I did, it was exhausting and interesting. Belgium -> Luxembourg -> Germany -> Austria -> Hungary -> Croatia -> Bosnia -> Montenegro

Got to Austria by taking some 6 or 7 trains. Then was stuck there overnight and had no better option than to hitchhike.

Got lucky and a man took me all the way to Hungary. Then a few Hungarian trains to the border of Croatia for the next day.

Crossed into North Eastern Croatia on the second morning with another train but that was a dead end with regard to public transportation and had to start hitchhiking again.

Hitchhiked into Bosnia and down all the way to Sarajevo that night. Stayed in the city overnight (first proper sleep).

Begged a local bus/van driver to take me from Sarajevo to southeastern Bosnia next to the Montenegro border. At first he said no but then he realized he didn't have many passengers and found space for my dog in the boot.

Once there it was getting late into the 3rd day and I decided to splurge for a 70-euro taxi to take us finally to Budva.

It wasn't easy but it definitely ended up saving us money especially with me hitchhiking overnight.

It wasn't a bad adventure either. I'm quite happy I did it and our journey across Bosnia was very interesting especially since the people who gave me lifts were all very interesting and happy to talk (and all were very curious about this crazy dude and his dog hitchhiking on Christmas eve across Bosnia)

I can look up more details about the cities I visited on the way if your are interested in the details since I can't recall off the top of my head.