Please note that you alone can't make an item lag. The item lag occurs sometimes in an intervall.
Okay. I've tried everything here the results: (Tried on L2X - Kastien)
Test 1 - Trading with a friend:
How to:
1. Equip weapon
2. Spam BSPS/SS
3. Unequip weapon
4. Continue with 1. to 3. until an item lag occurs
5a. If enchantement fail open Tradingwindow (all during item lag)
-> doesn't work
5b. If enchantement fail open Tradingwindow and insert the weapon (all during item lag)
-> doesn't work
5c. If enchantement fail open Tradingwindow and insert the weapon and trade it (all during item lag)
-> doesn't work
Test 2 - Warehouse
How to:
1. Open chat window with the warehouse-keeper
2. Equip weapon
3. Spam BSPS/SS
4. Unequip weapon
5. Continue with 1. to 3. until an item lag occurs
6a. If enchantement fail press the "Deposit" Option (all during item lag)
-> doesn't work
6b. If enchantement fail press the "Deposit" Option and deposit the weapon by pressing "Confirm/Okay" (all during item lag)
-> doesn't work
Facts: Doesn't Matter if the result of the enchantement is Success (S), Fail (F), F, F, S or S, F, S or F, S, S, S or F, F, S, S, S, or F, F, F, S
The first enchantement result (success or fail) is the final result!
Note: One strange thing...It seems easier to enchant a weapon this way and it seems that it wouldn't fail so often as going the normal way. Well, this is not a fact it could be imagination.