I reuse all my plastic bottles but my method for cleaning is a little OCD.
First, I rinse with hot water.
Then I put a dab of dish soap in each, fill with water, shake vigorously and dump
Then I throw them into a pot, fill the pot with water, and boil for ~30 minutes.
After that's done, I give it one more good rinse with hot water before setting them on my dish rack to dry.
I've never had an issue with flavors leeching but be careful when you're boiling them, water tends to evaporate and if you don't fill the pot back up - you risk burning your bottles!