Press your lips together, add vocal cord vibration, then release.

Americans pronounce bathroom as BATH-room (/ˈbæθˌrum/). Stress falls on the first syllable — keep everything else short and quick. You'll hear it in sentences like "The light in the bathroom is not working" or "The bathroom is occupied, so I will have to wait my turn" — more examples below.
Record yourself saying "bathroom" and play it back. The mic stays on your device — nothing's uploaded.
2 syllables, 6 sounds. Tap a syllable to jump to its row, then explore each sound's mouth shape and how it's made.
Press your lips together, add vocal cord vibration, then release.

Drop the jaw noticeably. Keep the body of the tongue low and forward, and don't let the back of the tongue raise toward the soft palate. Pull the lip corners back slightly, almost a starting smile.

Place the very tip of your tongue slightly between your teeth. Blow air gently around it without voicing.

Curl or bunch your tongue without letting the tip touch the roof of your mouth. Brace the sides of your tongue against your upper back teeth, and round your lips slightly.
Round your lips into a tight circle. Let your tongue rest in the middle of your mouth, slightly raised.
Press your lips together. Air flows through your nose. Vocal cords vibrate.

Click any sentence to see the full breakdown — every link, every reduction, every flap-T.
The textbook way isn't wrong — it's just not how anyone actually says it.
Stress falls on the first syllable, not the others. Stretch BATH — keep everything else short and quick.