Are there any alternatives to silicone sheets? I have a small part of my scar that has pleating - will that go away over time?

Silicone sheeting is most helpful on my opinion.  I usually start this treatment 2-4 weeks after surgery.   The pleating that you see will resolve.  

I have heard numerous scar treatment options in my career - everything from aloe vera and cocoa butter to horse liniment and emu oil.  The fact that there are so many of them tells me that none of them is perfect or else we would all be using it.  Silicone sheets are one option but they have to be kept clean and they may be hard to get to adhere to the skin.  You did not mention how long ago your surgery was, but most pleating will resolve within a couple of weeks to a month.  It actually takes a full year to a year and a half for a scar to fully flatten and mature.  If you still have pleating or an unsatisfactory scar after a reasonable amount of time then this portion of your scar may need to be revised.

Silicone is the most effective treatment in scar management. As an alternative to the sheets though, BioCorneum is a great product that works in a similar way. It's a gel that you apply to the scars twice a day that dries like a "silicone sheet." Much easier than applying the sheets daily. Hope this helps!

One product that I have found very beneficial for scar managment is Scar recovery gel from SkinMedica

There are many alternatives to silicone sheeting, and most of them are not terribly effective. Scars often soften and mature just with the passage of time. (Several weeks/months)

Scars change and mature over 6-12 months.  Massage in the early months can frequently help.  Paper tape, such as 3M Micropore tape, has also been found to help scars. (a number of years ago this study was published in our primary journal "Plastic and Reconstructive Surgery" as it applied to breast reduction patient's scars).  In some cases it is more effective than silicone sheeting. There are some silicone gel creams that may help also.  I sometimes wonder whether it is the massage or the cream or just time that is most helpful.