With a spray bottle, spray the side of a large beaker so that it's wet
With the same spray bottle again, put the back of the filter against the wet side of the beaker, and spray against the glass, in case any fine particles of gold go through they will be washed down the side of the beaker to the bottom. Spray all the material in your filter down to the bottom of your beaker until your filter is clean. Store the filter in a safe place until you have enough of them to incinerate, there might be small particles of Au still stuck in the filter paper.
When you precipitate Au, it should fall to the bottom of your beaker, and you should not need to filter it, instead you should be decanting it, meaning you can pour off the solution without pouring out the Au. There are many different ways you can wash and decant Au, and each of us I think has their own way of doing it. But I think most of us would agree that decanting when doing our washes is the best way, and that filtering isn't really the proper way of doing it.
Also, your material looks really light, creamy even, this leads me to believe you don't only have Au, that there might be other metals in your filter paper, like tin for example. So after you wash your material off your filter, you should re-digest in AR. If there was tin oxide in your solution AR will not digest it because it's insoluble in AR, so at this point you should filter while your Au is in solution, removing any material that didn't dissolve, and washing the material in your filter with water to ensure you are getting all your Au solution (AuCl).
After filtering you should be left with a nice gold colored solution, test with Stannous Chloride just to make sure then upon a positive result, precipitate your Au as you would normally. If your Au is of high purity it will tend to want to clump making it easier to wash and decant.
I am not giving you a step by step instruction in this post on everything you need to do to accomplish what I am suggesting, for example I made no mention to expand your solution with water and ice before precipitating, etc. I am assuming you know these steps and will incorporate them in what I am suggesting you do. I'm fairly certain however, just by looking at your pictures that there is something else with your Au, the color looks wrong to me. So a second digestion in AR should resolve this issue.
One last thing, if the whitish material is not tin oxide and happens to be lead, you should remove this when you re-digest in AR by adding a few drops of Sulfuric Acid, it only takes a few drops. If it is some other type of metal, then it might require a different method to remove and you should post here if you are not sure, and I'm sure someone here will attempt to help you further. I am just taking wild guesses based on my own experience but I might not be right about what I am suggesting the white material is.
Scott
