I, too, have had had less than great results with the magic eraser. It sometimes embeds streaks and dark marks into plastic. I think that the friction from the material heats the plastic up and can embed undesirable materials into the plastic.
Here's another recipe for cleaning plastic that I've been keeping to myself because I didn't know whether or not it's old hat and I wasn't certain how people would respond to it. It's cheap and it's quickly and easily made with household ingredients that I already have on hand.
I used to be in the sewing machine business. To keep people buying new machines, I would have to take trade-ins. As I'm certain we all have experienced in the vacuum world, one person's concept of "Excellent Condition" or "Like New" can vary from another person's. I used to end up with a lot of sewing machines that had stains from fabric coloring rubbing off onto the machine beds, black streak marks on the plastic sewing machine cases, and so on.
Like most of the people I have read about in this discussion forum, I also love refurbishing something to pristine cosmetic condition. Therefore, I would cosmetically refurbish the machines extensively, trying to replace as few trim pieces as possible.
The good news in terms of applying my experience to the realm of vacuum cleaners is that most of the plastics and paints used in modern sewing machines are very similar to the plastics and paints used in modern vacuum cleaners.
(If anyone's ever interested in my take on which is better plastic vs. metal machines--vacuums or sewing machines, just send me an email).
I used to make a paste out of Windex and baking soda to polish the marks out of the plastic and painted surfaces. Start with the baking soda, spray in a little Windex until it's a loose paste, put it onto a cloth, and gently buff and scour the surface of the machine to take out marks. It can sometimes take a little bit of pressure, but nothing heavy or extraordinary. Always test an inconspicuous spot first before trying this on a more obvious part of a vacuum. Be careful not to wipe too hard on surfaces that have screen-printed or painted logos, as I would be concerned that any abrasive or solvent/oil-based product (like car wax or Brasso) could erode the printing/paint.
I prefer this paste to other products for two reasons:
1. Because Windex is a dilution of ammonia with other cleansers and alcohol, so it dries quickly and does not remain in contact with plastic surfaces for extended periods of time. Car waxes and other solvent-based cleansers are usually petroleum or non-petroleum oil based, which I have found can cause degradation of color in some plastics if the products are left on for too long.
2. The baking soda gives a nice, very fine level of abrasive that quickly breaks down and that does not tend to erode plastic surfaces (especially textured plastic) unless you really apply tremendous pressure and repeated scouring. You usually have a great deal of warning before you damage any surface texture, though, and it's tough to really go too far with this.
3. (I know that I wrote that I had 2 reasons) This paste is cheap to make and it consists of stuff that most of us already have around the house. You can also make the paste out of ammonia and baking soda, but I am sometimes concerned about whether there are negative effects of applying undiluted ammonia to plastic surfaces.
Maybe people have already been using this and I am not suggesting something new. I will, however, tell you that I usually gravitate to this as the best method for cleaning textured plastic surfaces before I move on to a solvent or petroleum/non-petroleum oil-based product.
There is one (very minor) down side, however. The baking soda can sometimes leave a very fine powdery residue that you'll have to wipe off. This is easy...simply spray a cloth with Windex or water and wipe off the residue.
Hope that this is a good contribution and that people who have never tried this paste give it a go.
