Ow...you dont need to leave the etchant on for so long. Many people are surprised at how agressive lemon juice can be as an etchant. The topogrophical textures of Indo keris is made just by lemon juice. What I would suggest right now is to wash the blade with soap and water, and then oil it a bit with a penetrating oil like WD-40. Let it sit for a bit and then scrub lightly with 0000 steel wool. This will help get rid of any active rust, and will help even out the finish.
Here are tips for at least what has helped me in etching.
1. Always make sure the blade is properly degreased. Even the slightest bits of grease from even just fingerprint can screw things up. I normally wash the blade with hot water and dish soap a few times, after drying I then wipe it down a few times with rubbing alcohol and paper towels. Acetone works well also instead of rubbing alcohol.
2. Warm blade and etchant helps the etchant bite better. If its a hot summer day, leaving you etchant and blade out in the sun for a few hours works. However since its winter, heres what I do. I take the bottle of etchant (ferric chloride or lemon juice) and sit it in front of my heat vent for a while (an hour or two) to help it warm up. After wiping the blade down with alcohol (last stage of degreasing. I then light up the propane torch and give it a few quick passes (I stress quick) over the blade to warm it up a bit. Again youre not looking for red hot, just looking to warm up the blade a bit.
3. Brushing the etchant works great. When Im ready to etch I usually brush the etchant on with a tooth brush. The agitation helps the etchant spread evenly, and keeps it from settling. I dont soak the blade, instead I just stand it up or hold it and continually brush on the etchant.
4. Multiple short etches instead of singular long ones. I prefer doing a five 5 minute etch cycles over one long one. Meaning etch the blade, wash (neutralize acids), remove oxides (oil and steel wool), degrease, and repeat. I prefer this method, because if you make a mistake, or the etchant doesnt settle right the first time round, if you let it sit too long it burns its way into the steel (hope that makes sense) making more un-even patterns more common. Whereas with multiple short etches, un-even patterns dont get burned into the steel, you can keep an eye on progress, etc...
5. Keep an eye on it. If you have done thing right, the etch should be darn near instant. Dont over burn the blade in one pass. Keep an eye on it, and stop when things start to look like theyre going nowhere.
6. While supposedly the stable oxides created by etching should help prevent rust, Ive noticed blades that are recently etched are more succeptable to rusting early on. Meaning, for the first couple months after etching the blade is more sensitive to rusting. One explanation Ive heard is that the etchant opens up the pores of the steel. Well for whatever reason, keep an eye on your blade for the first couple months, and keep it well oiled. After that, it does stay pretty neutral.
7. ooh before I forget, texture in the steel means texture in the etch. So make sure your blade is perfectly smooth before etching. The magic polish is somewhat misleading, as its super shiny. Just because you can see yourself in you blade doesnt mean its perfectly smooth. So you may want to sand it first to even out the finish. However sometimes the funky patterns of the texture looks neat, kinda like fake damascus.
Well those are my tips for etching, hope they help.