Tracks. Glass. Screens. Frames. All clean.

Three common causes: (1) Cleaning in direct sunlight — the solution dries before you can wipe it, leaving residue. Clean in shade or on overcast days. (2) Using commercial glass cleaner on top of old residue — layers of ammonia-based cleaner streak. Switch to vinegar solution and start fresh. (3) Using paper towels — they leave lint fibers on the glass. Switch to microfiber cloths or crumpled newspaper. The two-cloth method (wet wipe + dry buff) eliminates streaks.

For large windows and sliding glass doors: absolutely. A good squeegee ($8–15) covers a large surface in one continuous pull, which eliminates the streak-causing stops and starts of cloth wiping. For standard-size house windows: the two-cloth microfiber method is equally effective and doesn't require mastering squeegee technique. Buy one if you have large windows or glass doors. Otherwise: microfiber is fine.

No. Fog or condensation between the panes of a double-pane (insulated glass) window means the seal has failed. Moisture has entered the space between the panes and there's no way to reach it from outside. Options: replace the glass unit (the double-pane insert, not the entire window frame, typically $150–300 per window) or hire a defogging service that drills a tiny hole, evacuates the moisture, and reseals ($75–150). This is a seal failure, not a cleaning problem.

Many double-hung windows tilt inward for cleaning (check for tilt latches at the top of the lower sash). Casement windows crank outward, making the outside accessible from inside. For fixed/picture windows on upper floors: a long-handled squeegee or mop ($15–25) reaches from the ground or through an adjacent window. For genuinely inaccessible windows: this is the one case where hiring a professional ($5–10 per window) is worth it.

Almost certainly. The baking soda + vinegar fizz dissolves compacted grime, the toothbrush scrub removes loosened debris from the grooves, and the flush clears the channel. After cleaning: apply a thin coat of silicone spray or car wax to the track — the window will slide smoother than when it was new. If the window still sticks after a thorough track cleaning: the rollers or track hardware may be damaged, which is a repair issue rather than a cleaning one.