I personally have altered over a hundred formals and wedding gowns and can certainly understand your concerns. With Georgette I have always used my serger on the raw edge after measuring for the hem length. Then turned under 1/4" and used a loose stitch all the way around. Then turned it up once again to hide this with a 1/2" hem, did this on all the hems until I got my serger. Now I simply trim off the excess, serge the edge, fold up the hem to the length I want, press it well and either use the roll hem foot or hand stitch. In a pinch I've even used fabric glue in a pinch but don't really recommend it for georgette - It leaves a mark on the fabric that in some colors is really noticable. There is also something called steam a seam but it will melt the fabric - So don't use this stuff. I learned this the hard way. Ugh!