Can someone enlighten about this FD sweep-in facility from HDFC Bank :

What my RM explained sounded too good to be true and I literally couldn't find much information about it over the internet.
Not to confuse with auto sweep facility, in case of auto sweep, above a certain threshold amount, the remaining amount's FD is created automatically but in case of FD sweep-in, one has to create a FD and then choose to enabled sweep-in for it.
So, I'll tell you what my RM explained, let's say I've 3L in my savings account and I create FD of 3L for 15 months 1 day at interest of 7% p.a. and then enabled FD sweep-in. For sweep-in, I'll get a lesser interest, 6.5% p.a. and I've no idea if deducting 0.5% p.a. is the fixed norm or not. Say, I transact for Rs. 100 after 5 days of FD being created, it will be deducted/broken from FD amount and I'll get interest at 6.5% p.a. for 5 days, is that true?
I've several questions, someone who has used this first hand, please comment below.
If this scheme is as good as it sounds, it will be a great as FD rates are fairly decent currently and having liquidity as well as no premature withdrawal charges in addition to getting rates as promised (with a minor deduction of 0.5% p.a. from regular rate).